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Old 11-11-2012, 11:34 PM   #33 (permalink)
DocsMachine
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Quote:
Originally Posted by HP_Lovecraft View Post
On a related note, wasnt this also the reason that SP switched to 2pc barrels?
-SP switched to 2 piece barrels for ease of manufacturing and cost-cutting.

As I noted earlier, SP started out buying factory barrels straight from the manufacturers. That wasn't going to keep working forever (IE, what if Bud decided to stop selling them to SP, and decided to start drilling them himself?) so SP started setting up to make their own.

Now, keep in mind I'm only speculating here, but I'm making kind of an informed speculation. Anyway, SP almost certainly found out that making barrels is actually pretty tricky. You either drill from solid bar stock, or you have tubing custom-extruded to the dimensions you want, and just finish-machine the surfaces.

I suspect they started with bar stock, at least early on, because you have to make huge purchases for custom extrusions- like committing to buy 5,000 feet or more.

As an aside, this is part of the reason Bob Long developed the Intimidator- he'd set up to make fancy aftermarket milled bodies for the Spyder, and bought a huge run of custom extrusion to do it. But it turned out nobody wanted to put a $250 body on $150 blowback, so he wound up stuck with thousands of feet of custom extrusion. But, a little fiddling and inventing later, they fitted it with electro guts and called it the Intimidator.

Anyway, whether SP used solid bar or custom extrusion, they probably found out that boring them accurately much past 5" or 6" was difficult- and, I suspect, they started out early on with used machinery that couldn't hold tolerances that well, and got worse the deeper the bore went.

Now, the other side of that coin is that the existing SP barrels had started to get a nasty reputation of being very hard to clean. The ports essentially "stored" paint, so even after multiple squeegeeings, it'd still shoot like it had a wet bore.

SP had already put a bunch or marketing into the "rifled" concept- including the famous "high speed" photos from the ad- so they couldn't just drop the porting. That was the whole and only reason anyone bought the darn things.

So somewhere along the line, somebody at SP had a bright idea: Make the barrels in two parts. That let them to several things: One, make tips in bulk. Rather than setting up for a complete barrel, one machine could be set up to do nothing but tips, while others did back halves of various threads.

That way, each half of the barrel was relatively short, and thus easy to machine. (In part the same reason so many makers today produce two-piece barrels instead of full-length one piece. Even with today's high-end machines, it's tricky to make a good, smooth, accurate-diameter bore that deep.)

Second, the tip section could be made larger in bore diameter, so that broken paint wasn't as hard on accuracy as it was for the straight-bores. Chances are SP found an off-the-shelf tubing size, and just used it rather than going with a more expensive custom extrusion.

Third, the tips could now be custom-anodized and assembled separately. Instead of having (just as an example) five different barrel threads and five different colors of anno (meaning you'd have to keep 25 different barrels on hand to fill any one color/thread combo order) you could just have a bin of back and a bin of tips- somebody wants a 'Cocker barrel with a purple tip, you just grab an appropriate back and a matching tip. Glue 'em together and ship 'em off.

This is one of the things that really helped SP early on; they not only had custom barrels, they had custom barrels for damn near everything. Other makers (and there were damn few early on) might have had 'Mag, 'Cocker and VM barrels, but SP had those three plus Illustrator and Z1 and Bushmaster and Storm, etc. etc. and so on.

They could do that because it was a trivial exercise to reprogram a machine to make a slightly different thread, then jam a tip in to finish 'em off.

Quote:
The story I've always heard was that SP discovered it was cheaper to use 3/4" tube stock to make the barrels, then use 1" bar stock to make the "backs"
-As above, probably. It all comes down to cost: Making short pieces and joining them is cheaper than boring a single piece (accurately) in the same length, and using off-the-shelf tubing is cheaper than buying custom-size extrusions.

And as far as cost goes, note how early SP barrels had tight spirals of very closely-spaced holes. Many of the very earliest (hand drilled factory barrels) had the holes damn near touching.

Later mass production barrels, however, used a shallower spiral and considerably looser hole spacing. So instead of (again, just to throw a number out) 100 holes in a line, there might only be 30. Less drilling means reduced cycle time, means more made per machine hour, which of course means more profit. And I don't begrudge 'em that a bit, except for all the early advertising about the rifling and ball physics...

Quote:
Then.... market this as being better then 1pc. Because of magic fairies or whatever.
-Actually, SP was selling the 2-piece barrels for years before it got to be common knowledge they even were 2-piece. The early marketing was all about the "rifling"- making the ball spin, "disconnecting" the ball from the gas column allowing to "regain it's shape" after firing, etc. etc.

I mean, people did know they were 2-piece (the tip would sometimes fall out) but that fact wasn't mentioned in the advertising 'til several years down the road.

Doc.
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